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The pages below describe various aspects of Telematics and TCU, TCU Basics and Architecture of a Modern TCU.Also coverered are the modern Trends and innovation in the Telematics industry.
#intro Telematics and TCU
The TCU(Telematics Control Unit) is a small computer which makes integrated use of
telecommunications and informatics, also known
as ICT (Information and Communications Technology)
in a modern automotive vehicle to listen in on the communications of other Electronic Control Units(ECUs) in
the car, then interprets and disperses that data as necessary using various Wireless Communication techniques .
Today Telematics has taken a turn towards the future and all possible applications are being suggested for a TCU. TCU is the primary communication module which connects the automobile to the external world. TCU is mainly responsible for emergency assistance, road-side assistance, information services, remote door lock/unlock assistance, remote diagnostics etc. It incorporates the most advanced technologies viz. Bluetooth, in-vehicle Wi-Fi (AP and Client), internet-radio, Off-board navigation (GPS), dead reckoning etc.
Applications of the TCU are described in later sections.
#arch Architecture of a Modern TCU
A hypothetical TCU with multiple Interfaces and Controllers is shown below.
As seen from the figure the TCU broadly contains an Application Processor (AP) which the heart and soul of the Telematics System. This processor is the heart of the System and interacts with all the other processors to extract data, Analyse, Process, and Packetize and transmit the information related to multiple applications to the Telematics Operations Centre (TOC).
#intcon Interfaces and Controllers
The rest of the Controllers have been segregated based on their Interaction with different Networks/Components
Vehicle Communication Interfaces
CAN Controllers
The CAN Controller can either be a peripheral of the Application Processor or a separate Controller in itself. The primary function of the CAN controller would be to Interact with the CAN bus and sniff messages and relay them to the AP. It also acts a channel for AP to send Commands to different ECUs in the car as described earlier.
The modern TCU mostly uses the CAN for the following purposes:
Acquisition of Crash Data during a Crash. This can be as simple as a Crash has occurred to where exactly the Crash has occurred in terms of the Point [Frontal / Rear/ Side/ Rollover/ Multiple] of Impact and the Severity of Impact [Severe/Medium/Light].
Acquisition of Vehicle Data such as VIN, Odometer Reading, Fuel Status.
Acquisition of Ignition Status.
Acquisition of Door Status.
Acquisition of Door Lock Status.
Acquisition of Passenger Occupancy Status.
Acquisition of Data from the Vehicle Radio for various uses such as Muting the Vehicle Audio during Calls ,getting the appropriate Language to play the prompts etc.
Acquisition of Oil Change Information to send Maintenance Status Reports .
Acquisition of DTC (Diagnostics Trouble Codes) Data to inform the OEM/Service Provider about a non-scheduled problem with the vehicle.
Acquisition of the HFM[Hands Free Module] Status to keep the Audio System awake during a HFM Call.
Interaction with Diagnostic Tools over CAN for Vehicle Diagnostics and Software Upgrades.
As observed from the above use-cases the TCU sniffs data from the various ECUs for various purposes .In certain instances it also controls the actions of other ECUs by issuing various commands to them as in cases listed below.
Control of the Door Lock Status in case of Remote Door Lock/Unlock
Setting of the Audio System Volume in case of TCU initiated Calls.
MOST Controllers
The Most Controller can be integrated effectively with the AP/Wireless Controllers to stream infotainment data directly to the in-Vehicle Radio or video devices.
Wireless Communication Interfaces
GSM /GPRS Terrestrial Interface Processor
UMTS/CDMA Processor
WiMAX Interface Processor
Satellite Communication Processor
In-Vehicle Device Communication Interfaces
Bluetooth Processor
The Bluetooth Processor acts as an Interface between the Bluetooth Modules like phones in a Car and the TCU.The Bluetooth phone can get paired with the TCU and all the calls can be routed through the MICs and the Audio System of the vehicle
Wi-fi Controller
The Wi-Fi Controller combined with the Wireless Communication Processors are intended to transform the car into a Wi-fi hotspot.
Audio Processor
GPS Interface
The intent of the GPS processor is to extract the current position all the time in addition to the timestamp .Important information such as NMEA streams can be extracted from the GPS data which can be later plotted to track the exact movement of the vehicle.
#features Functions of a TCU
Crash Detection and Reporting – In case of a crash, the TCU detects and reports the Crash data to the TOC with lots of other data such as Current location extracted from the GPS and vehicle information extracted from the CAN. This data can be either sent over SMS or GPRS/3G(GSM)/UMTS(CDMA). In addition a Call is placed to the TCC(Telematics Call Centre)which enables the occupant to talk to the Call Centre executive and report his wellness.
Roadside Assistance – The Occupant can reach the Call Centre by a user initiated Call from the vehicle. The current location of the vehicle is reported and a call is placed to the Call Centre.
Stolen Vehicle Tracking - This feature enables the User/TCC to track his vehicle by letting the TCC know once the vehicle is stolen. Multiple options are available to Call centre user to Check the current location of the vehicle. They can be done either periodically or at any desired point in time.
Remote Door Lock/Unlock – The Owner of the vehicle can request the Call Centre if the vehicle gets locked or he forgets to lock his vehicle. In which case the TCC can remotely either Un-lock the doors for him or lock them depending upon the scenario.
Software Upgrade OTA – The TCU software can be remotely upgraded OTA to add new features or fix earlier issues.
Maintenance Status Reports – The TCU can send Periodic Maintenance Status Reports to the TOC to provide a Complete Health Report of the vehicle. This data can be used effectively to intimate the Car dealership/Owner about Scheduled/Un-scheduled Maintenance .
Remote Diagnostics – The TCU can be used for Remote Diagnosis of the vehicle .This is apart from the MSR which is generally a Periodic Report. The Remote Diagnostics feature performs a Full System Scan of all/most Vehicle Computers(ECUs)and provides a report .
Handsfree Module Support – The TCU can sync with the Handsfree Modules like phones over Bluetooth or Vehicle Adapters over CAN and handle all calls through the Vehicle Speakers and Microphone generally built in the Rear View mirror. Also Phone Books can be managed via Bluetooth from supported phones.
In-Vehicle Wi-fi – As described earlier the TCU can provide streaming internet directly to a Occupant while he is on the move.
Recent Developments in Telematics and Integration of Advanced Mobile phones like Iphone have opened up a huge potential for both Telematics and Iphone Application Developers in the space of Automotive Embedded Appications.
The Article below just gives an example of the same.
http://www.nytimes.com/2009/02/15/automobiles/15TECH.html?_r=3&ref=technology
http://www.pcmag.com/article2/0,2817,2246496,00.asp
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